1. Field of the Invention
This invention generally relates to integrated circuit (IC) fabrication and, more particularly, to a thin-film transistor (TFT) with a vertical channel region, and an associated fabrication process.
2. Description of the Related Art
The size of TFTs formed in liquid crystal display (LCD) processes are limited by the resolution of large panel photolithography tools. Currently, the resolution of feature sizes is about 0.5 microns (um) and larger. High-speed circuit operation requires a TFT capable of high drive current and low parasitic capacitance. These characteristics are obtained by shrinking the device size, especially the transistor channel length. For example, conventional production CMOS technology uses transistor channel lengths of 90 nanometers (nm), and lower, for very high-speed operation.
To further the enhancement of TFT drive currents and switching speeds, it would be desirable if the channel length of TFT devices could be made smaller than the resolution of photolithographic tools.